Jack



Sept. 8, 1925.

O. PERGANDE JACK Filed July 5, 1921 m m n w.

Sept. s, 1925.

O. PERGANDE JACK Filed July 5, 1921 2 Shan -Shut 2 INVENTQR ATTORNEY Patented Sept. 8, 1925.

UNITED STATES o'rTo PERGANDE, or MILWA KEE, WISCONSIN.

JACK.

Application filed July 5, 1921.

To all whom it may concern:

Be it known that I, OTTo PERGANDE, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of l/Visconsin, have invented new and useful Improvements in Jacks, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification.

This invention has for its object to pro vide a jack of the ratchet type capable of either a lifting or lowering movement according to the angle of swing of the lever handle and without requiring the manipulation of a catch or other hand operated means.

lVith the above and other objects in view, the invention consists in the jack as herein claimed and all equivalents.

Referring to the accompanying drawings, in which like characters of reference inclicate the same parts in different views:

Fig. 1 is an elevation of a jack constructed in accordance with this invention, the front plate thereof being removed, the handle being near its lowermost position while the operating parts are in condition for raising the jack;

Fig. 2 is a sectional view thereof on the plane of line 2-2 of Fig. 1;

Fig. 3 is a sectional view showing the position of the parts when the handle is thrown to its uppermost position for lowering the jack;

Fig. 4: is an elevation showing the parts in such position of the handle and showing the spring under tension for retracting the pawl;

Fig. 5 is a sectional view showing the engagement of the dog with the cam wall of the casing for returning it into engagement with the rack on the following downward stroke of the handle;

Fig. 6 is a view showing the positions of the parts at the end of the downward stroke of the handle, the dog having lifted the rack permitting the spring to retract the pawl so that the rack is lowered during the following upward stroke of the handle; and

Fig. 7 is a perspective view of the spring plate.

In these drawings 10 indicates a standard having the casing 11 formed therewith as Serial No. 482,503.

usual, and containing the dog and pawl mechanism, while 1-3 is the usual sliding rack for lifting the load.

A lever 14 is fulcrum'ed in the casing at 15 and is provided with a socket to receive a handle 16 as usual, and a dog member 17 pivoted at 18 between the side plates of the lever member engages the teeth of the rack for raising or lowering it. The dog 17 is urged toward or away from the teeth of the rack by means of a spring 19 which is fixed at one end in the lever member and bears on a forked pin or projection 20 on the dog. The spring is preferably in the form of a wire fitting in the fork of the projection 20 and adapted to bear in a slot 21 at the end of the dog. Inthe position of the parts shown in Fig. 3, the spring serves to hold the dog away from the rack, but in the position of the parts shown in Figs. 1 and 6 it urges the dog toward the rac A pawl 22 is fulcru'med in the lower part of the housing and is urged by a spring 23 either toward the teeth of therack or away therefrom. This spring is also preferably a wire spring and is carried by a plate 24 which is pivotally mounted on a screw 25 threaded in the housing. The plate is of sheet metal and where the screw 25 passes through it it is bent over as shown in Fig. 7, so as to have a spring action that will tend to hold it in place on the screw notwithstanding that tensionthat is given to the spring 23. By bending a flap on the plate 24 in this manner the screw passes through two openings, one in the flap and the other in the plate proper, and the spring action of the bent flap against the end of the screw, while the plate bears on the base of the casing, serves to give the necessary frictional engagement to hold the plate in its respective positions. This frictional engageinent may be varied by tightening or loosening the screw 25 and such adjustment is retained by the cover plate 26, which is held with screws to the flange surrounding the opening in the casing bearing tightly against said screw head, as shown in Fig. 2.

The spring plate 24: is influenced by the position of the dog 17 so as to shift back and forth between the positions shown in Figs. 1 and 4. A pin 27 projecting from the rear wall of the casing not only forms a stop for the pawl when it is retracted from the rack, as shown in Fig. 6, but forms an abutment against which the lower end of the dog 17 strikes when the handle is thrown to a position higher than is neces sary for the dog to engage the next tooth of the rack when elevating the load. In other words, the dog does not strike pin 27 during the normal lifting operation of the but when the handle'is rais'edhigher than for the normal lifting operation, such engage ment throws the dog back to the position shown in Fig. 3, carrying the fork 20 on the spring to a point where the spring tends to hold the dog back in this position. In this backward movement of the dog it effects the throw of the spring plate 24: because of a lug 28 on the dog engaging a flange 29 bentswing back to the position shown in Fig. 1

back from the edge of the plate. In thus swinging the plate 24 the tension of spring 23 is reversed so that instead of urging the pawl 22 toward the rack, as in Fig. 1, it urges it toward the stop pin 27 as in Fig. 6. During the succeeding-downward stroke of the handle the dog 17 is brought into engagement with the upper wall of the housing, as shown in Fig. 5, and is directed thereby toward the rack soas to engage one of the teeth of the rack and slightly lift the rack just before the handlereaches the end of its downward stroke. This takes the load off the pawl 22 which is therefore retracted by spring 23 so that the load will be lowered with the dog during the following upward stroke of the handle. I

During the downward movement of the dog in lowering the load, the pin 28 engages a flange 30 of the spring plate and by riding on said flange causes the spring plate to and thus urge the pawl 22 into engagement with the rack. This lowering operation wlll be repeated with each stroke of the handle that is preceded by the full raised position thereof shown in Figs. 3 and 4, but at other times when the handle is only moved through its ordinary stroke, the spring plate 24' remains in the position shown in Fig. 1 and the operation of the dog and pawl mechanism is the same as usual.

Not only is it possible to raise or lower the jack by merely varying the length of stroke of the handle, but it is possible to disconnect both dog and pawl from the rack to permit the rack to drop, for quickly collapsing the jack after the work is done.

This is accomplished by merely moving the handle to the positions shown in Figs. 3

and 4: to retract the dog and then lifting the rack to permit the spring 23 to retract the pawl. The rack is then free to slide without engagement by either the dog or the pawl.

What I claim as new and desire to secure by Letters Patent is:

1. In a jack having a sliding rack with a pawl for engaging its teeth, a lever having a dog for engaging the teeth of the rack, means for imparting a spring action to the pawl in one position thereof to urge the pawl away from the rack, and a stop in the path of'the dog for moving it to a position in which it will escape its engagement with the teeth of the rack when the lever is moved beyond its normal stroke, said dog engaging said spring means at such time to move it to the position for urging the pawl away from the rack.

2. In a jack,a sliding rack, a pawl for engaging the teeth thereof, a lever carrying a dog for engaging the teeth of the rack, means operated by the swing of the lever for moving the dog out of engaging position,

and means operated by the dog whenso moved to urge the pawl out of engagement with the rack teeth.

3. In a jack, a slidable rack bar, a pawl for engaging the teeth thereof, a lever, a dog fulcrumed on the lever for engaging the teeth of the rack bar, a pivotally mounted plate having friction means for holding it in its different positions, a spring carried thereby and engaging the pawl for urging the pawl toward or away from the rack bar, means for throwing the dog out of engagement with the teeth. of the rack bar when the lever is moved beyond its normal stroke, and means on the dog for engaging the plate to change the position of the plate when the position of the dog is changed.

4. In a jack, a casing, a rack bar slidably mounted thereon, a pawl pivotally mounted in the casing for engaging the teeth of the rack bar, a lever fulcrumed in the casing, a dog pivotally mounted thereon and adapted to engage. the teeth of the rack bar, a spring bearing on the dog for urging the dog toward or away from the rack teeth,

a stop pin in the casing engaged by the dog when the lever is moved beyond its normal stroke for swinging the dog away from the rack teeth, cam means for returning the dog to the rack teeth, a pin on the dog, a friction plate pivotally -mounted on the casing, flanges projecting from the friction plate and engaged by the pin on the dog for swinging the plate, and a spring carried by the friction plate and engaging the pawl for urging the pawl toward or away from the rack teeth.

in testimony whereof I affix my signature.

OTTO' PERGANDE. 

